Electric conductor



2 Sheets-S'ht 1.

(N0 Mode 1.)

s. TAINTER ELECTRIC CONDUCTOR.

No. 289,725. Patented Dec. 4, 1883.

N. PETERS. Fmwumo hu. wzshln tnn. D. c.

(No Model.) 2 Sheets-Sheet 2.

I s. TAINTER. ELECTRIC GONDUGTOR.

No. 289,725. Patented 1360.4; 1883.

JW f v Qu/finiOZy M m mi I my. aim) W iaw UNITED STATES PATENT SUMNER TAINTER, OF IVASHINGTOX, DISTRICT OF COLUMBIA.

ELECTRIC CONDUCTOP.

SPECIFICATION forming part of Letters Patent No. 289,725, dated December 4, 1883,

Application filed June 22, 1383. (No model.)

To aZZ whom it may concern.-

Be it known that I, SUMXER TAIXTER, of XVashington, in the District of Columbia, have invented a new and useful Improvement in the Manufacture of Electric Conductors for Telephonic and other Purposes, which improvement is fully set forth in the following specification.

This invention has reference to the manufacture of compound conductors or cables con taining two or more concentric insulated conductors-that is, acentral conductor surrounded by one or more tubular conductors insulated from said central conductor and from each other-and particularly of anti-induction compound conductors for telephone-lines, the said conductors containing two conductors, which are to be connected so that one forms the direct and the other the return branch of the circuit. As an anti-induction compound conductor the concentric form is superior to that in which the two branches of the circuit are twisted together in the following respects: First, the action of a neighboring conductor upon the branches will be equal at every point, whereas in the case of a pair of insulated wires twisted together there are local disturbances, produced by the inequality in the distance of the two branches from the disturbing source; second, the conductor occupies less space than a pair of twisted wires of equal conductivity, which is advantageous when a number are to be packed together in a cable.

Heretofore it has been proposed to make compound conductors or cables by depositing metal electrically upon an insulated conductor, the electroplating constituting the exterior tubular conductor; also, by surrounding an insulated conductor with a series of wires laid along side and in contact with one another, so as to constitute an exterior tubular conductor 5 also, by enveloping an insulated conductor in metal foil; also, by pressing a leaden tube or sheath on an insulated conductor, and also by coiling one insulated conductor around another.

The present invention consists, first, in the formation of the exterior tubular conductor by folding one or more metal strips longitudinally around an insulated conductor. This strip can be readily and cheaply applied by means of a conical die.

It has been proposed to fold a strip around a bare wire and to reduce the covered wire, one die serving both purposes. This mode of formation differs from the present invention, 5 5 in that no insulating material is used, that the wire and its coating form one conductor instead of two, and that the central core is re duced by drawing.

In carrying out this invention the strip is 60 preferably ofsuch width as to fit snugly around the central insulated conductor without or with but little further stretching or compression in the die than is required to produce a close fit.

By using an insulating material which admits 6 5 of reduction, the core could be reduced in the act of applying the covering, and such an operation would be within the scope of this part of the invention. As many strips as desired may be applied successively, one in contact with the other, so that they form one conductor, or with the interposition of insulating material, so as to form a series of conductors. The insulating material is preferably of the improved kind set forth below, and is applied at the 7 same time with the conducting'strip; but it may under this part of the invention be of any ordinary or suitable construction, and may be previously applied. For example, the folded metal strip or strips can be applied to an ordinary gutta-pereha-covered wire or wire covered with other known or suitable insulating material. In making anti-induction cables care should be taken to have the insulating material of uniform thickness, so that the axes S5 of the two conductors will coincide; otherwise disturbance is likely to result from the inequalities.

The invention secondly consists in forming a tubular conductor of two or more longitudinally-folded strips of metal, arranged so that the joints between the folded-over edges occur at different points of the circumference, or, in other words, so that the folded strips break joints. This part of the invention includes the application of two or more strips, not only to an insulated conductor, which is its pri1nary object, but also to a core generally-as, for example, to a bare wire, to a core of insulating material, or to a removable core. The

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tubular conductor formed of two or more metal strips folded longitudinally, and arranged to i break joints, may therefore constitute not only I one of a series of two or more concentric conductors, but the sole conductor of a strand; or it may form part of a larger conductor.

The invention consists, thirdly, in coating the strip or strips to be folded with parafline or similar water-proof material, the object being protection from infiltration of water by the stopping of all pores and small spaces with the paraffine or plastic,water-proof material. This part of the invention includes the coating of the strip or strips, not only when they are to be applied to an insulated conductor, but also generally when strips are to be folded longitudinally around a core.

The invention consists, fourthly, in insulating a conductor with a strip or strips of paraflined paper, or paper coated or impregnated with other insulating material, or otherwise rendered insulating, or of other fabric suitably coated, impregnated, or prepared, folded longitudinally around the conductor to be insulated. The folding may be performed by a die, and the folded strip or strips are preferably held in place by the folded metal strip or strips of an exterior tubular conductor; and this combination constitutes the fifth part of the invention. Under the fourth part of the invention the folded insulating strip or strips may be held in place by wrapping, or by a sheathing or covering of any suitable description. Preference is given to the paraffined paper for the insulating material on account of the excellency and uniformity of its insulation, its low cost, its uniform thickness, and the capacity for uniting or welding together at the edges, so as to form an unbroken tube.

The invention comprises as well the improved conductors as new articles of manufactures as the methods employed in their pro duetion.

The inventionfurther comprises certain constructions, arrangements, and combinations of dies, guides, reels, and other apparatus which are or may be used in carrying into effect the improved method or for making the improved conductors.

The following description will enable those skilled in the art to which the present invention relates to make and use the same, reference being had to the accompanying drawings, which form a part of this specification.

Figure 1 is a view in side elevation, partly in section, showing the new or improved apparatus, and illustrating also the manner of using the same. Fig. 2 is a similar view, showing certain additions that may usefully be made thereto; Figs. 3, 4, 4, 5, and 6, detail views, showing the construction of the dies. Figs. 7, S, 9, and are perspective views, showing short pieces of compound conductors made in accordance with the invention, the parts at one end of each piece being separated to show the construction; and Fig. 11 is a front elevation, partly in section, showing a cutting apparatus.

The apparatus shown is designed for making the wires shown in Figs. 8 and 9, which are the most perfect embodiments of the illvention.

The reels A B CD, of ordinary construction, are supported in the frame E, so that they are free to turn. The diesF Gare held stationary in suitable holders attached to or forming part of said frame. Set-screws are employed to retain them in position, so as to permit their removal when desired. The die F is in two parts, a Z), the dividingline being oblique to the longitudinal axis of the die. The main or upper part, a, (see Figs. 1, 3, and 4,)is a hollow cylinder having a conical bore, in which the lower portion, at the enlarged end of the cone, has been removed. The part I) occupies the space of the removed portion. It is pro; vided at the front part with an open groove, 0, equal in width to the insulating-strip, and also with asmall hole, d, leading into the conical space. The hole cl is a guide for the central conductor or wire, 6. The groove 0 is a guide for the insulating-stripf, the semicircular space at the enlarged end of the die is a guide for the metal strip 9, and the hollow cone folds the strips ff/ around the central conductor, 0. The dividingline between the parts of the die is made oblique, and at such a position that edges of the strips, in folding, will rub against the upper surface of the part b, which will therefore form edge-guides for the folded strips and prevent them from accidentally changing their correct relative position. This isconsidered the best form of die but it is evident that modifications could be made. The guide for the central conductor or wire is useful in insuring to the same an axial position. The guides for the insulating and the conducting strips prevent them from changing their relative positions. Guides outside of the die could be used; but it is an improvement to make them part thereof, since they then continue their control during foldmg.

The die G is a cylinder, with conical bore, or, in other words, a plain conical die. It is provided with a cap-piece, L, provided with an axial guide-opening. h, for the conductor after it leaves the die F, and a guide-slit, m, for the second metal strip, a. The slit in is on the opposite side of the central conductor from the guides for the first conducting-strip, 9, so that when folded the joints at the edges of the two strips will be on opposite sides of the conductor. The slit m acts also as a scraper, to prevent excess of paraffine from entering the die. A reel for receiving the finished article is or may be used. \Vire for the central conductor, e, is wound upon the reel A. It may be bare wire, or wire covered with cotton or silk, or otherwise provided with a uniform preparatory coating. It is preferably copper,

but may be of iron or steel or other ductile or flexible metal. The insulatin g-strip f is wound 011 the reel B. It is preferably paper soaked in paraiiine. Stout Manila wrapping-paper is suited to the purpose. It is cut into strips, I in Fig.2, and the wire and strips passed through which are run through a bath of melted para-ffine, which is allowed to harden thereon. It is very desirable to have the strips of uniform width, and it has been found that a sufficient uniformity is not secured without great care on the part of the operator (if at all) by use of a cutter and guide.

To secure an exact uniformity, the apparatus shown in Fig. 11 has been devised. It consists of a double pair of rotary shears, having their cutters arranged to cut or trim simultaneously both edges of the strip. The upper pair of cutters, p, are fixed on a shaft, P, which is revolved by suitable means, and are separated by a washer, 0, which can be removed and replaced by one of different thickness, in order to vary the distance between the cutters and the consequent width of the strip cut thereby. The lower cutters, q, are fixed on a shaft, Q, and one of them is, or both may be, made adjustable by a setscrew. The space between the washer r and the lower cutters, q, is equal to the thickness of the material to be cut, so as to exert a clamping action thereon. The journals of the shaft Q do not reach to the ends of the bearings, so that the lower cutters adapt their position readily and perfectly to that of the upper ones. I It is obvious that other suitable cutting apparatus could be used. The metal strips 9 a are cut from a sheet of metal, or are otherwise made. It is not so necessary, owing to the ductility of the metal, that they should be of exactly equal width throughout, and a single pair of rotary shears with a guide may be advantageously used. Copper is preferred for the strips, although iron or other metal adapted to be folded could be used. The strips are run through a bath of melted para'ftine, and are then wound, the strip 9 on the reel 0 and the strip a on the reel D. The wire a, insulating-strip f, and conducting-strip g are led from their reels over one or more supports to and through the die F. The ends are then clamped and drawn through said die. To facilitate the introduction, the ends of the strips are pointed. As the elements cf 9 are drawn through the die, the strips f g are folded tightly around the central conductor, 0. The paraftine thorough- 1y fills all spaces between the folded-over metal strip 5 and the insulating-strip f. Vhen a sufficient length of the compound conductor has been drawn through the die F, the end, together with the end of the second metal strip, 02, is passed through the die G. The drawing through folds the said second strip, oz, closely around the former. The end of the finished conductor or cable is secured to the receiving or drawing reel, and by revolving it the elements will be progressively drawn from their reels, united into a cable, and wound upon the said receiving or drawing reel.

Instead of previ ously coating the m etal strips, or even the paper itself, with parafiine or similar waterproof or insulating material, a bath, M, may be placed in front of the dies, as shown .the same on their way to said dies. The dies also may be heated, to retain the paraffine or its equivalent in a liquid or semi-liquid condition in passing through. The compound con ductor or cable shown in Fig. 7 has only a single folded-over metal strip, 9, for the tubular conductor, and could be made with the apparatus shownin Figs. 1 and 2 by omitting the reel D and guide G. The central conductor is shown as provided with a fibrous (cotton or silk) covering; but this could be omitted. In Figs. 8 and 9 the two strips 11 are shown. In the conductor or cable shown in Fig. 8 the central wire is cot-ton covered. In Fig. 9 the conductor is insulated only by the paraffine strip of papcrf. In Fig. 10 the cable or conductor has three concentric conductors, the central conductor, (2, and the folded metal strips 9 each insulated by paraffine strips f. It could be formed by duplicating the die F and introducing an insulating-strip into both.

As shown, the folded conductors are each of a single thickness; but they could be doubled by the use of dies G after each die F. If more than a double thickness is desired for a tubular conductor, it is obvious that as many additional folded strips as desired could be laid 011 by the use of a succession of dies G. The relative resistance between the exterior and interior conductors may readily be regulated by using metal strips of proper size. In a cable wherein the two concentric c011- ductors are to be connected in metallic circuit, their resistances would, or, when desirable, might, be the same.

Modifications may be made in detail without departing from the spirit of the invention, and parts of the invention could be separately used. The central conductor could be a tube instead of awire, and may be formed in any suitable way. The compound conductors or cables may, of course, be covered wit-h insulating material, or be protected in any known or suitable manner. It is found that the providing of the die with edge-guides oblique to the axis of the diesuch as furnished by the upper surface of the part I), as illustrated in the drawings, so that the strips are guided during the folding operation-is very important in securing their correct relative position, and that these cdgeguides or this guiding-surface could be usefully employed without the guiding groove and hole shown and described, although not so advantageously as with them.

Owing to the limited space, the bath M in Fig. 2 is shown so disposed that the strips are bent rather more sharply than is desirable. In practice they should enter and leave the liquid at a gentle incline, the means commonly employed in galvanizing and temper ing wire or other suitable means being employed for the purpose.

Having thus described my said invention and the manner of carrying the same into effect, what I claim is 1. A tubular conductor comprising two or more metal strips longitudinally folded, and arranged to break joints, substantially as described.

2. A tubular conductor formed of one or more metal strips longitudinally folded, and coated with material-such as paraffinc substantially as described.

3. A compound conductor or cable comprising an insulated central conductor enveloped in one or more folded metal strips, and having the spaces between the folded strips and the central insulated conductor filled with materialsuch as paraffinesubstantial1y as described.

4. The combination, with a foldingdie, of two or more strip-guides arranged on the same side of the axis of the die, for preserving the proper relative position of the two strips in passing through the die, substantially as described.

5. The two-part folding-die having a conical bore, and provided with guides for the strips to be folded, substantially as described.

6. The combination of the reels for the central conductor, for the insulating-strip,and for the metal strip or strips of the guides and the folding die or dies, substantially as described.

7. The combination, with two or more folding-dies constructed to fold each strip entirely around the core, and arranged in series, of

strip-guides for the several guides arranged on different sides of the axes thereof, so that the j oints in the folded stripswill be at different points in the circumference of the tube formed by the folded strips,substantially as described.

8. The method of insulating conductors by enveloping the same in a folded strip of paper treated with insulating materialsuch as paraffinesnbstantially as described:

ductors by enveloping the central conductor with paper treated with insulating material such as parafline-and folding around said coating one or more metal strips, substantially as described.

11. A compound conductor comprising a central conductor, a surrounding coating of paper treated with insulating material-such as paraffine-and an exterior conductor of one or more folded metal strips insulated from the central conductor by said paper, substantially as described.

12. A compound conductor comprising c011- centric conductors separated by an even thickness of insulating material formed of a folded insulating-strip, substantially as described.

13. A folding-die provided with oblique edgeguidcs opposite the enlarged end of the cone, so as to guide the edges of the strips during folding, substantially as described.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

SUMNER TAINTER.

Witnesses:

A. PoLLoK, PHILIP MAURO. 

